Values specific for weighted records - Amazon Route 53

Values specific for weighted records

When you create weighted records, you specify the following values.

Routing policy

Select Weighted.

Record name

Enter the name of the domain or subdomain that you want to route traffic for. The default value is the name of the hosted zone.

Note

If you're creating a record that has the same name as the hosted zone, don't enter a value (for example, an @ symbol) in the Record name field.

Enter the same name for all of the records in the group of weighted records.

For more information about record names, see Record name.

Record type

The DNS record type. For more information, see Supported DNS record types.

Select the same value for all of the records in the group of weighted records.

TTL (seconds)

The amount of time, in seconds, that you want DNS recursive resolvers to cache information about this record. If you specify a longer value (for example, 172800 seconds, or two days), you reduce the number of calls that DNS recursive resolvers must make to Route 53 to get the latest information in this record. This has the effect of reducing latency and reducing your bill for Route 53 service. For more information, see How Amazon Route 53 routes traffic for your domain.

However, if you specify a longer value for TTL, it takes longer for changes to the record (for example, a new IP address) to take effect because recursive resolvers use the values in their cache for longer periods before they ask Route 53 for the latest information. If you're changing settings for a domain or subdomain that's already in use, we recommend that you initially specify a shorter value, such as 300 seconds, and increase the value after you confirm that the new settings are correct.

If you're associating this record with a health check, we recommend that you specify a TTL of 60 seconds or less so clients respond quickly to changes in health status.

You must specify the same value for TTL for all of the records in this group of weighted records.

Note

If you create two or more weighted records that have the same name and type, and you specify different values for TTL, Route 53 changes the value of TTL for all of the records to the last value that you specified.

If a group of weighted records includes one or more weighted alias records that are routing traffic to an ELB load balancer, we recommend that you specify a TTL of 60 seconds for all of the non-alias weighted records that have the same name and type. Values other than 60 seconds (the TTL for load balancers) will change the effect of the values that you specify for Weight.

Value/Route traffic to

Choose IP address or another value depending on the record type. Enter a value that is appropriate for the value of Record type. For all types except CNAME, you can enter more than one value. Enter each value on a separate line.

You can route traffic to, or specify the following values:

  • A — IPv4 address

  • AAAA — IPv6 address

  • CAA — Certificate Authority Authorization

  • CNAME — Canonical name

  • MX — Mail exchange

  • NAPTR — Name Authority Pointer

  • PTR — Pointer

  • SPF — Sender Policy Framework

  • SRV — Service locator

  • TXT — Text

For more information about the above values, see Value/Route traffic to.

Weight

A value that determines the proportion of DNS queries that Route 53 responds to using the current record. Route 53 calculates the sum of the weights for the records that have the same combination of DNS name and type. Route 53 then responds to queries based on the ratio of a resource's weight to the total.

You can't create non-weighted records that have the same values for Record name and Record type as weighted records.

Enter an integer between 0 and 255. To disable routing to a resource, set Weight to 0. If you set Weight to 0 for all of the records in the group, traffic is routed to all resources with equal probability. This ensures that you don't accidentally disable routing for a group of weighted records.

The effect of setting Weight to 0 is different when you associate health checks with weighted records. For more information, see How Amazon Route 53 chooses records when health checking is configured.

Health check

Select a health check if you want Route 53 to check the health of a specified endpoint and to respond to DNS queries using this record only when the endpoint is healthy.

Route 53 doesn't check the health of the endpoint specified in the record, for example, the endpoint specified by the IP address in the Value field. When you select a health check for a record, Route 53 checks the health of the endpoint that you specified in the health check. For information about how Route 53 determines whether an endpoint is healthy, see How Amazon Route 53 determines whether a health check is healthy.

Associating a health check with a record is useful only when Route 53 is choosing between two or more records to respond to a DNS query, and you want Route 53 to base the choice in part on the status of a health check. Use health checks only in the following configurations:

  • You're checking the health of all of the records in a group of records that have the same name, type, and routing policy (such as failover or weighted records), and you specify health check IDs for all the records. If the health check for a record specifies an endpoint that is not healthy, Route 53 stops responding to queries using the value for that record.

  • You select Yes for Evaluate target health for an alias record or the records in a group of failover alias, geolocation alias, latency alias, or weighted alias record. If the alias records reference non-alias records in the same hosted zone, you must also specify health checks for the referenced records.

If your health checks specify the endpoint only by domain name, we recommend that you create a separate health check for each endpoint. For example, create a health check for each HTTP server that is serving content for www.example.com. For the value of Domain name, specify the domain name of the server (such as us-east-2-www.example.com), not the name of the records (example.com).

Important

In this configuration, if you create a health check for which the value of Domain name matches the name of the records and then associate the health check with those records, health check results will be unpredictable.

Record ID

Enter a value that uniquely identifies this record in the group of weighted records.